Racking on yeast cake to restart fermentation?

I have a big RIS that started at 1.100 and is now stuck at 1.034. It's on WLP001, from a stir-plate starter (~400 billion cells). I suspect aeration caused the stall as I use the 'shake' method to aerate.

It started out vigorously, but is now without question stuck (2 weeks unchanged). Most everything I can find says to rack it onto a new yeast cake and the combination of a little bit of oxygen and the new cake will get it going again.

My next planned batch is a citra hopped XPA, somewhere in the 60 IBU range. I'm pretty sure this RIS could hide anything at this point. The RIS is already 90+ IBU from magnum/goldings.

Are any off flavors from the yeast cake from a citra hopped beer going to show up in the RIS?

Any dangers in reusing the yeast cake? (autolysis, trub, over-pitched to restart, ....)

Theoretically those fears of pitching on top of an active yeast cake are valid. In practice, I've been doing that for several years with up to five brews in a series without touching the yeast cake. I haven't once noticed any of the expected off flavors. That doesn't mean they aren't there, but I can't taste them. Maybe NHC would catch them...

Cheers,
Scott

What did you mash at? 1.034 seems like a pretty reasonable FG for a 1.100 stout.

maskednegator said:

What did you mash at? 1.034 seems like a pretty reasonable FG for a 1.100 stout.

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Mashed at 156. Expected this to come down to 1.024 with this yeast strain (~10% ABV) in line with commercial RIS examples. It's quite sweet tasting right now that I don't think carbonation will help at this point.

I think you're done. 66% attenuation seems a little low, but I'd believe it on a huge beer, mashed at 156, and with probably a good bit of specialty grains.

Even if you're not confident about your starter methods, the fact is you at least grew your yeast a significant amount. So I wouldn't blame the starter.

When something goes wrong with my beers, I'm a big fan of just letting it ride, enjoying the beer I made, and correcting any mistakes next time. It seems just as likely that you could fix your beer by tampering with it as making it worse.